Last year, Nintendo announced they would temporarily cease production for the Nintendo Switch Splatoon 2 set, in favor of ramping up production for the Super Mario Odyssey set.
It appears that production is about to resume soon, as Rakuten Books has reopened pre-orders for the Splatoon 2 hardware bundle today. In addition, pre-orders for the set will come with the Splatoon 2 Splategy Guide, which has so far been only announced for the Splatoon 2 Starter Edition in North America.
Update – Ships on March 17, 2018. Available on Amazon Japan (doesn’t ship worldwide).